In an automatic weapon fed by a cartridge belt, the belt generally has a great length and it is stored in a casing in overlapping coils and a guide passageway connects the casing to the feed apparatus of the weapon.
It is known that for high firing rates, substantial forces are brought into play due to the fact that the mass presented by the length of the belt must be put in movement and also due to the friction forces between the belt and the walls with which they are in contact (walls of the ammunition casing, guide passage, etc.).
Without special precautions, there can be produced firing errors such as faulty introduction of the cartridge in the chamber of the weapon, jamming of the weapon, etc.
It has therefore been proposed to avoid these firing errors by providing an apparatus for applying traction to the belt directly activated by the weapon but such apparatus includes complex mechanisms and necessitates sometimes a modification of the weapon.